Automatic mechanism for player pianos



w. B. TUNSTALL.

AUTOMATIC MECHAMSM FOB PLAYER PIANOS.

' APPucA'lon men nmzsnazi.

1,430,340, Pmwdsepf 2&6, 1922.

- Fg. i5"

/NVEN rag; lf f5,

4w. B.. TUNSTALL.

A AUTOMATIC MECHANISM F0 YER PIANOS.

' APPLICATION FILED IA ,1921.

l 1,430,340. Patentedsept. 2 22. f

'v 2SHEETSS Patented Sept. 26, l1922.7

UNITED STATES y `1,430,340 PATENT4 oFFlcE.

u/'ILLIAi/r B. TnNsTALL, or WORCESTER, MASSACHUSETTS.

AUTOMATIC MECHANISM FoR PLAYER rPIANos. f I

T0allwhomitmag/00710677111: i

Be it known that I, VILLIAM B. TUN- sTALL, a cit-izen of the United States residing atWorcester, in the county ofWorcestei and State 'of Massachusetts, have invented new and useful v.Improvements in `Automatic Mechanismlfor Player Pianos, of

vating system requiring a minimum of future adjustments while still allowing of convenient accessibility -to internal and obstructed parts when said adjustments' may be necessary.

Of thef accompanying drawingsfo-rniinga i `part of this speciication,-- i

Figure 1is an end elevation, showing the exterior of astructure embodying the invention. f n i Figure 2 is a fragmentary view, showing in vertical section portions of the structure shown by Figure 1. e l

Figure 3 is a view'` similar to Figure 2, illustrating a `different stage of the operation. 4 Figure 4 is a ure 2. v f

Figure 5 is a section online 5--5 of Figure 2. i

Figure 6 is a fragmentary enlargement of a portion of Figure 4. f i f f Figure 7 is an enlarged sectional view of the primary ,pneumatic shown bv Figure 2.

The same Ireference characters indicate the same parts in all of the figures.

Figure 1, showing in end elevation a structure embodying the automatic mechanism of my invention, also shows a portion 12 ofa piano key, a sticker or abstract 13, arranged section `on line 4-`-4 of Figto be lifted bythe. key, and a hammer 14` connected as usual with thewippen 15,

mounted on the sticker, these elements being adapted to be operated in the ordinary way in manual playing, the sticker resting loosely on the key, so' that it may be lifted.

independently byy a power pneumatic form-- ing an element of the automatic mechanism hereinafter described. n i v 16 represents-the usual tracker-bar .having a row Of Qritices or ports 16a, each ar- Application` led January 28, 1921. Seria1`No.`440,`589.

ranged to be closed by an imperforate `portion of anote sheet 17, and opened when laperforation 17 n in the sheet registers with the port, the sheet being engaged "with a driven take-up spool 18, and `with a supply `spool 19. The tracker-bagnote sheet, and

spools are supported by a frame 20. Each tracker-bar port is connected by a tube 21,

`with` a horizontaltube rail 22, removably -mounted on the horizontal top board or 'member 23 of a'casingiwhich is suitably secured tothe frameof the piano, said tube rail bein detachably secured at,v its outer edge, as, ereinafter described, Vto member 25 o-f--said casing. The tube rail-22 constitutesthe base of a superstructure which is supported by'said casing.. andv includes the frame 20 `and suitable standards 24' attached yto the frame and the tube-rail.

Theca sing, of which the lmember 23 forms the top, includes a `vertical outer channel `board 25 forming the front, `anda `vertical inner channel fboai'd 26 forming the .-back, of the casing. Y The said channel boards are and tliespace betweenthese channel boards is subdivided into chambers, of ywhich there are two, one `being a vacuum chamber 29 in which a partial vacuum is maintained `by the suctioiiapparatus of the instrument, op-` erated by the usual pumping pedals, or other` vacuum producing means,A The` other isan open chamber 30 in communication `with .i the atmosphere. The channel boards 25 and 26 form the outerl and inner uprightwalls jbottom of a vacuum, chamber ,29 and the ,top of an open4 chamber 30. The bottomy of said vopeny chamber is formed by a horizontal pneumatic board 31, also abutting :against the outer channel board.

i The part 28. is called ay valve board-.because it is provided lwith avertical passage .33, and with valve seats 34 and 35, yat opposite ends thereof, cooperating with the valves i hereinafter described. `The part is called :ga pneumatic board because yto it is secured the ...-XM1, .member .0f a Primary pneumatic,

26-is fixed a i n spaced apart,as shown byFigures-2, Band 4, n

:of these chambers, the-.opposite ends ofthe located in the open chamber 30. Said pneumatic is preferably composed of a discoidal fixed member 36, a discoidal movable member 362l and anA annular band 36h, of membrane or thin skin secured to said members.

The vacuum chamber 29 connected by a suitable conduit with the suction appa'- ratus, not shown, a portion of saidf conduit, as here shown, being a nipple 38 iixed to and extending through the inner channel board 26. The open chamber 30 communicates with the outside air through an oritice 39.

The power pneumatic. shown in section by Figure `2, includes a fixed member 40, secured to a fixed channeled arm, or power pneumatic rail 41, on the inner channel board 26, a movable member 404 hingedly connected at one end to the member. 40, and a flexible Wall portion 40b connected with the members 40 and 40?. I

The channel 42 of the power pneumatic rail 41 communicates with a channel 43 in the inner channel board, and the last-named channel communicates through a branch channel 44 with thel passage 33 in the valve board. IThe channels 42, 43, 44, and the passage 33 collectively constitute a power conduit which is instrumental in causing the operation of the power pneumatic. The tube rail 22 has'a channel 45 communicating with a channel 46 in the outer channel board. A branch channel 47 in the pneumatic board 31 connects the channel 46 with passages 48 in the fixed member of the primary pneumatic, said member being rigidly secured to the board 31. The passages 45, 46, 47 and 48 collectively constitute a primary-con duit, which is a. continuation of' a trackerbar tube 21.

yA vacuum chamber valve 49 cooperates with the valve seat 34, and an open chamber valve 50 cooperates with the valve seat in controlling the movement of air through the above-mentionedl power conduit. Said valves are connected with a. stem 5l', which is lixed at 52 to the movable member of the primary pneumatic, and is vertically movable in a i'ixed. guide 53 in the vacuum chamber. The area of the pneumatic member 36a is greater than that of the vacuum chamber valve 49, for a purpose hereinafter described. T he vacuum chamber valve is preferably loose on the stem 51` and controlled by the latter through suitable enlargement, such as a collar 5la secured to the stem.

The vacuum chamber 29- coimnunicates, through a contracted vent, with the primary conduit channel 46' in the outer channel board, said ventA being preferably provided by inserting in an ori'fice'in the inner side of said channel board. and' communicating with the channel'` 46, a flanged sheetl metal cup having an orifice 56v (Figure 6) of much smaller diameter than the 'chenille/11y The operation is as follows:

Vhen a traclrerebar port is closed by an imperforate portion of the note sheet, as shown by Figure 2, and vacuum is produced in the chamber 29, the primary pneumatic is collapsed, and the movable member thereof is drawn toward the fixed member, as shown by Figure Q, this collapse being duc to the fact that the atmospheric pressure in the open chamber 30 is exerted on thc exterior of the primary pneumatic, and is prevented from acting on the interior thereof by the note sheet, so that the atmospheric pressure on the primary pneumatic is unbalanced. The contracted vent 56 facilitates the col lapse of the primary pneumatic by permif ting the withdrawal, or an' induced flow of a limited quant-ity of air from the interior of the primary pneumatic to the vvacuum chamber, asindicated@ by arrows in Figure 2. The contraction of the vent 56 is such that the air passing through it to the vacuum chamber, when atmospheric pressure prevails in the primary conduit, does not appreciably affect or nullify the vacuum in said chamber. The valve stem 5l is thus drawn downward and seats the vacuum chamber valve 49 and opens the open chamber valve 50, so that atmospheric pressure is admitted to the interior of the power pneumatic, as shown by arrow z/ in Figure 2. rFhe pressure of the valve 49 against its seat is determined by the difference between the area of the pneumatic member 36L and that of the valve, the area of the member 36?l being in all casesI greater than the area of the valve 49. 1 have, therefore, made provision for insuring a wind-tight closure of'the valve 49 on its seat during this period of the operation, this provision being of much importance, because the success of.a. player piano depends almost entirely on the wind-tightness of its valve system. Any leakage of air around the valves will impair the control by the operator of the dynamics of the instrument.

Under the conditions thus far described, atmospheric pressure is balanced on the inside and outside of the power pneumatic. lVhen, however, a perforation in thc note sheet registers with the tracker port now being considered, air is forced by atmospheric pressure through the tube 2l, and terminates the vacuum in the channel 46 and in the primary pneumatic, so that the movable member' 36 is no longer held down. Atmospheric pressure entering the interior of the primary pneumatic neutralizes the vpulling. power of the latter, allowing the atmosphere to close the valve 50 and force open the valve 49, causing an induced low of air from the power pneumatic to the vacuum chamber 29, as indicated by arrow in Figure 3, and allowing the atmospheric vpressure to force the movable member 40" of `inner side of the-outer channel board may I casing, preferably by screws GO" detachably "tube rail `is made air-tig 6i thepower 'pneumatic upward.` The hammer la is, therefore, caused to strike `a blow throughthe usual connections between the powerpneumaticand the hammer.

The :induced flow of air from theipower pneumatic to the vacuum chamber is in the direction of the opening movement ofthe 'valve 49,l and yfacilitates said' movement.

It will be readily understood that this ar-l rangement of the valve system materially helps to improve'the touch of the pneumatic mechanism, as the motion of the valve, the travel of the air and themovement of the f power or striking pneumatic` all workin unison andtoward the samev end. It is a well known `fact that the tone color of la piano depends largely upon the arrangement andmethod of attack and-by this improved system of valve mechanism, the best -Ipossible results in this direction are attained. i y y y v The casing forming they chambers 29 and 30 is preferably constructed to be easily and conveniently opened to permit access to said chambers, the valves, and the primary pneumatics. To this end I detachably "connect the casing member formed by the outer channel board 25 to the body portion of the casing formed by the other casing members, preferably by screws 60, the removal of said screws permitting the removal of the outer `channel board, and as this board forms the outer or front wall ofthe casing, it follows that its removal leaves the chambers open at the front side of the body portion of the casing.v To ensure air-tight oints when the outer channel board isattached, I lprovide packing 'material at 61, of any suitable compressible substance,y preferably formed as facing strips glued tothe edges ofthe members ofthe casing body against which the outerchannel board abuts. Ifdesired, the

be faced with packing material. I l AThe tube rail 22 forms" the'blase ofa superstructure which includes the standards 24 f and the frame 20, the standards being fixed tothe tubei'rail. i l

To permit the removal of said superstructure and convenient' raccess tothe power pneumatics and other mechanism behind the above-described casing, Idetachably secure i the tube r rail 22 to the top portionof said connecting the' upper lendy lportion of'ithe outer channel board 25 with the tube rail," the channel board being extendedto overlap theV forward `edge of thestube rail.A When the screws GO?L areremoved, the entire super'- y structure`may 'be lifted' fromi-the casing.

The tuberail channels 45 register 'with the channels 46 of the outer lchannel board and the joint between therchannel Aboard and ht by packing atla.l The primary pneumatic members 36"'a11d causing said induced flow.

rigid material,\andthe*flexible member 36b` is preferablyan annular strip of thin leather or membraneattachedv at its edges to the perimeters of said disks. To cause `the Hexible member to bag inward and provide suitablefrictionless flexibility, I corrugate its central zone, by turningy one of the discoidal members relatively to the other, untilthe annular member is twisted sufficiently to formwell definedv wrinkles or corrugations 63, as indicated by Figure 7, these corruga- `struction permits a maximum. of 'movement n and `a minimum .of lost motion, and eliminates angles or corners in the flexible member, so that liability of; cracking when corners occur is obviated. 1

Iclaim:` v l. An automatic i mechanism. for player pianos, comprising a collapsible power pneul matic, atracker-barhaving airports controlledby a perforated notesheet, a casing intermediate the power pneumaticand the tracker-bar, subdivided tov form*I a' vacuum chamber communicating with suction apparatus, and an .open chamber communicatingl #with the atmosphere, a power conduit connecting the interior'of the power pneumatic `with both chambers,rand cooperative means ytions being practically frictionless when the v pneumatic is openingand closing. This conwhereby, when a tracker-bar port is closed,

the power pneumatic is connected with the open chamber and disconnected fromthe vacuum chamber, and when said port is opened, the power pneumatic is disconnected from the'openlchamber, and connected with the vacuum chamber to permit an induced flow of air from the power pneumatic to the vacuum chamber, and the collapse of the power pneumatic by external atmospheric pressure, said cooperative means including a valve and valve seat for controlling thepasi sage of air from said power'conduit to the vacuum chamber, the said valve seat beingy between` the :valve 'and the power conduit whereby/said valve, to open, moves in the .direction of said inducedy flow of air;l

2.v` An automatic mechanism for v player pianos, substantially as specified by claim 1, saidcooperative means including also a collapsible primary pneumatic 1in the open chamber, having a movable member 'connected with-thevacuum chamber valve, and

of greater areathanthe latter, and a primaryf conduit communicating with said tracker-,bar port and with 'the interior `'of the primary pneumatic, whereby when the said ort is closed, the primary 'pneumatic is colapsed by unbalanced yatmospheric pressure, I land draws ythefvacuum chamber'valve against its seat, andwhen the port isopened the primary pneumatic is neutralized, permitting the vacuumchamber toopen and 3. An automatic mechanism for player pianos, substantially as speciiied by claim l, said cooperative means including also a coll-apsible primary pneumatic in the open chamber having a movable member connected with the vacuum chamber valve, an open chamber valve connected with the primary pneumatic and with the vacuum chamber valve, and a primary `conduit communicating with said tracker-bar port and with the interior of the primary pneumatic, the aforesaid conduit being connected by means of a restricted air passage to thevacuum chamber, whereby when said port is closed,

the primary pneumatic is collapsed by un-y balanced atmospheric pressure, closes the vacuum chamber valve, and opens the open chamber valve, to permit a balanced atmospheric pressure on the powerpneumatic, and when the port is opened, the power of the primary pneumatic is neutralized, the vacuum chamber valve is released, and the open chamber valve is closed to allow an induced flow of air outward from the power pneumatic, permitting the latter to collapse.

4. An automatic mechanism for player pianos, substantially as specified by claim l, said cooperative means including also a collapsible primary pneumatic in the open chamber, having a movable member connected with the vacuum chamber valve, and of greater area than the latter, and a primary conduit communicating with said trackerbar port and with the interior of the primary pneumatic,whereby when the said port is closed, the primary pneumatic is collapsed by unbalancing the atmospheric pressure through an induced fiow of air from the primary pneumatic to the vacuum chamber, and draws the vacuum chamber valve against its seat, and when the port is opened, the primary pneumatic is neutralized, and releases the vacuum chamber valve to permit said induced flow, the said primary conduit being connected with the vacuum chamber by a contracted ventA which permits an induced flow of air from the interior of the primary pneumatic to the vacuum chamber,

suiicient to facilitate the collapse of the primary pneumatic, without nullifying the -vacuum in the vacuum chamber when atmospheric pressure prevails in the primary conduit.

5. In an automatic mechanism for player pianos, a casing composed of members including a rear, power pneumatic-supporting `channel board, a valve board, and a pneumatic board, both fixed to the rear channel board, atop board fixed to and projecting forward fromthe rear channel board, and afront channel board bearing on the forward edges of the valve board, the pneumatic board and the top board, said members forming walls of a vacuum chamber and an open chamber, suitable` vadditional casing members being provided to close the ends of said chambe' the front channel board being removably attached to the casing structure formed by the other members, to expose said chambers and permit access to the contents thereof, packing means being provided Yfor forming ai.r-tight joints when thev outer channel board is attached.

G. In an automatic mechanism for player pianos, in combination, a casing composed ci members including a rear, powerpneumatic-supporting channel board, a front channel board, `top board covering the space between said channel boards, and complemental members 'forming with the abovenamed members; .fi vacuum chamber and an open chamber within the casing; a superstructure compri. ng a frame supporting a tracker-bar and note sheet spools, a. tube rail forming the base of the superstructure, means connecting said iframe with the tube rail and tubes @tending from the trackeri bar to the tube rail, 'the tube rai] being removably seated on the top board of the casing, and detachably secured to the casing to permit the removal of 'the superstructliure and access to power pneumaticsbehind the rear channel board.

7. A primary pneumatic ttor player pianos, composedv of two rigid circular disks and an annular wall of flexible material, secured to and extending between said disks,`and provided between the disks withV corrugations formed by turning one disk relatively to the other, to twist said wall, said corrugations normally contracting the central Zone of the annular wall and causing the wall to bag inwardly.

8. In an automatic mechanism for player pianos, a casing comprising an inner channel board, supporting a power pneumatic, an outer channel board spaced from the inner board, a valve board and a pneumatic board forming, with the said channel boards, walls of a vacuum chamber communicating with suction apparatus, and an open chamber communicating with the atmosphere, a primary pneumatic supported by the pneumatic board, the inner channel board and valve board being provided vwith a power lconduit communicating with said chambers,

and the outer channel board being provided with a primary conduit communicating with the interior of the primary pneumatic, a `vacuum chamber valve, an open chamber i valve, and means connecting said valves with the primary pneumatic.

9. In an automatic mechanism for player pianos, a casing comprising an inner channel board, supporting a power pneumatic, an outer channel board spaced from the inner board, a valve board and a pneumatic board -forming, with the said channel boards,

Jwalls of a vacuum chamber communicating with suction apparatus, and ofv an open chamber communicating with the atmosphere, a primary pneumatic supported by the pneumatic board, the inner channel board and valve board being provided with a power conduit communicating with said chambers, and the outer channel board being provided with a primary conduit communicating with the interior of the primary pneumatic, a vacuum chamber valve, an open chamber valve, and means connecting said valves with the primary pneumatic, a contracted vent being provided connecting the primary conduit with the vacuum chamber.

10. An automatic mechanism for player pianos, substantially as specified by claim 1, said cooperative means including a vacuum chamber valve, an open chamber valve and a primary pneumatic connected with said valves, the power pneumatic, the valves and the primary pneumatic being arranged to move in the direction in which the said in` duced iiow of air is traveling when the said port is opened, said movements opening the vacuum chamber valve.

l1. In an automatic mechanism for player pianos, a casing includinga valve board forming a wall of a vacuum chamber and havingvalve seats in said chamber, and a detachably secured front board, constituting a removable wall of said chamber; and valves in said chamber; all of said'valves and valve seats being exposed' for inspection when saidffront board is removed.

12. In an automatic mechanism for player pianos, a casing including a vacuum chamber, a valve therein, a valve outside the vacuum chamber, a circular bellows-type primary pneumatic outside y the vacuum chamber,yand a stem connecting the primary pneumatic with the said valves, the said primary pneumatic and valves being movable 4by gravity to close the lvalve in the vacuum chamber. y

13. In an automatic mechanism for player pianos, a vacuum chamber, a power pneumatic, a power pneumatic conduit, and means for permitting the induction of a flow of air through said conduit to the vacuum chamber to cause the collapse of the power pneumatic by external atmospheric pressure, said means including a valve and valve seat for controlling the passage of airy acterized by seats for the said valves .tween the valves and the conduits which connect with the power pneumatics whereby the valves, to open, move in the same direction as that in which air flows when a power pneumatic operates.

In testimony whereof I have afiixed my signature. WILIAM B. TUNSTALL. 

